PineScript Basic Syntax

PineScript Basic Syntax

Understanding PineScript’s syntax is the foundation for writing effective trading indicators and strategies. This guide covers the essential syntax rules you need to know.

Script Structure

Every PineScript follows a basic structure:

//@version=6
indicator("Script Title", overlay=true)

// 1. Variable declarations
myVariable = close

// 2. Calculations
result = myVariable * 2

// 3. Plotting or strategy logic
plot(result)

Version Declaration

Always start with the version declaration:

//@version=6

This tells TradingView which version of PineScript you’re using. Version 5 is the latest and recommended version.

Script Type Declaration

Declare whether your script is an indicator or strategy:

// For indicators
indicator("My Indicator", overlay=true)

// For strategies
strategy("My Strategy", overlay=true, initial_capital=10000)

Key Parameters:

• overlay=true: Displays on the price chart
• overlay=false: Displays in a separate pane
• initial_capital: Starting capital for backtesting (strategies only)

Comments

Comments help document your code and are ignored during execution.

Single-Line Comments

// This is a single-line comment
sma20 = ta.sma(close, 20) // Calculate 20-period SMA

Multi-Line Comments

Caution

PineScript does not support traditional multi-line comments (/* */). Use multiple single-line comments instead:

// This is a longer explanation
// that spans multiple lines
// to describe complex logic

Indentation and Line Breaks

PineScript uses indentation to define code blocks (similar to Python).

Correct Indentation

if close > open
    // This code runs when condition is true
    bullish = true
    plot(close, color=color.green)
else
    // This code runs when condition is false
    bullish = false
    plot(close, color=color.red)

Line Continuation

For long lines, break them logically:

// Break at natural points
longCondition = ta.crossover(fastMA, slowMA) and
     rsi < 70 and
     volume > ta.sma(volume, 20)

// Use parentheses for expressions
result = (close * 0.5) +
         (open * 0.3) +
         (high * 0.2)

Variables

Variable Assignment

PineScript uses = for variable assignment:

// Simple assignment
price = close
length = 14

// Assignment with calculation
average = (high + low) / 2
rsiValue = ta.rsi(close, length)

Variable Naming Rules

✅ Valid Names:

myVariable
my_variable
myVariable2
_privateVar

❌ Invalid Names:

2myVariable  // Can't start with number
my-variable  // No hyphens
my variable  // No spaces

Built-in Variables

PineScript provides many built-in variables:

close    // Current close price
open     // Current open price
high     // Current high price
low      // Current low price
volume   // Current volume
time     // Current bar timestamp
bar_index // Current bar number

Operators

Arithmetic Operators

sum = 10 + 5      // Addition (15)
diff = 10 - 5     // Subtraction (5)
product = 10 * 5  // Multiplication (50)
quotient = 10 / 5 // Division (2)
remainder = 10 % 3 // Modulo (1)

Comparison Operators

equal = close == open        // Equal to
notEqual = close != open     // Not equal to
greater = close > open       // Greater than
greaterOrEqual = close >= open  // Greater than or equal
less = close < open         // Less than
lessOrEqual = close <= open // Less than or equal

Logical Operators

// AND: Both conditions must be true
longCondition = close > open and volume > 1000000

// OR: At least one condition must be true
exitCondition = close < lowThreshold or rsi > 70

// NOT: Inverts the condition
notBullish = not (close > open)

Conditional Statements

If Statement

if close > open
    barColor = color.green
else if close < open
    barColor = color.red
else
    barColor = color.gray

barcolor(barColor)

Ternary Operator

A shorthand for simple if-else statements:

// Syntax: condition ? valueIfTrue : valueIfFalse
barColor = close > open ? color.green : color.red

// Another example
trendDirection = close > ta.sma(close, 50) ? "Bullish" : "Bearish"

Functions

Built-in Functions

PineScript includes many built-in functions:

// Technical indicators
smaValue = ta.sma(close, 20)
rsiValue = ta.rsi(close, 14)
bbUpper = ta.bb(close, 20, 2)

// Math functions
absValue = math.abs(-10)     // 10
maxValue = math.max(10, 20)  // 20
sqrtValue = math.sqrt(16)    // 4

// Utility functions
crossUp = ta.crossover(fastMA, slowMA)
highest = ta.highest(high, 20)

Custom Functions

Define your own reusable functions:

// Simple function
getRangePercent() =>
    (high - low) / low * 100

// Function with parameters
getEMA(source, length) =>
    ta.ema(source, length)

// Using the functions
rangePercent = getRangePercent()
ema20 = getEMA(close, 20)

Plotting

Basic Plot

plot(close, color=color.blue, linewidth=2, title="Close Price")

Conditional Plotting

// Only plot when condition is true
plotchar = close > open ? close : na
plot(plotchar, color=color.green, title="Bullish Bars Only")

Multiple Plots

fastMA = ta.sma(close, 10)
slowMA = ta.sma(close, 20)

plot(fastMA, color=color.blue, title="Fast MA")
plot(slowMA, color=color.red, title="Slow MA")

Common Syntax Mistakes

❌ Mistake #1: Using var incorrectly

// Wrong: Declaring variable type
float myVariable = 10  // Don't specify type unless using var

// Correct: Simple assignment
myVariable = 10

// Correct: Using var for persistent variables
var cumulativeVolume = 0.0
cumulativeVolume := cumulativeVolume + volume

❌ Mistake #2: Forgetting indentation

// Wrong: No indentation
if close > open
plot(close, color=color.green)  // Error!

// Correct: Proper indentation
if close > open
    plot(close, color=color.green)

❌ Mistake #3: Using assignment in conditions

// Wrong: Using = instead of ==
if close = open  // Error!

// Correct: Use == for comparison
if close == open

Best Practices

1. Use Descriptive Names: movingAverage20 is better than ma or x
2. Add Comments: Explain why you’re doing something, not what
3. Keep It Simple: Break complex logic into smaller functions
4. Test Incrementally: Add features one at a time and test
5. Use Built-in Functions: Don’t reinvent the wheel

Try It Now

Copy this template to start coding:

//@version=5
indicator("My First Script", overlay=true)

// Your variables here
length = input.int(20, "MA Length")

// Your calculations here
ma = ta.sma(close, length)

// Your plotting here
plot(ma, color=color.blue, linewidth=2)

// Your alerts or strategy logic here
bullishCross = ta.crossover(close, ma)
alertcondition(bullishCross, title="Bullish Cross", message="Price crossed above MA!")

Next Steps

Now that you understand the basic syntax, learn about:

• Data Types & Variables - Deep dive into PineScript’s type system
• Operators - Master all operators and their precedence
• Your First Strategy - Build a complete trading strategy

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